f2fs: separate f2fs_gc_range() to use GC for a range

Make f2fs_gc_range() an extenal function to use it for GC for a range.
Signed-off-by: Daeho Jeong <daehojeong@google.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/gc.c

@@ -1975,10 +1975,34 @@ void f2fs_build_gc_manager(struct f2fs_sb_info *sbi)
 	init_atgc_management(sbi);
 }
 
+static int f2fs_gc_range(struct f2fs_sb_info *sbi,
+		unsigned int start_seg, unsigned int end_seg, bool dry_run)
+{
+	unsigned int segno;
+
+	for (segno = start_seg; segno <= end_seg; segno += SEGS_PER_SEC(sbi)) {
+		struct gc_inode_list gc_list = {
+			.ilist = LIST_HEAD_INIT(gc_list.ilist),
+			.iroot = RADIX_TREE_INIT(gc_list.iroot, GFP_NOFS),
+		};
+
+		do_garbage_collect(sbi, segno, &gc_list, FG_GC, true);
+		put_gc_inode(&gc_list);
+
+		if (!dry_run && get_valid_blocks(sbi, segno, true))
+			return -EAGAIN;
+
+		if (fatal_signal_pending(current))
+			return -ERESTARTSYS;
+	}
+
+	return 0;
+}
+
 static int free_segment_range(struct f2fs_sb_info *sbi,
-				unsigned int secs, bool gc_only)
+				unsigned int secs, bool dry_run)
 {
-	unsigned int segno, next_inuse, start, end;
+	unsigned int next_inuse, start, end;
 	struct cp_control cpc = { CP_RESIZE, 0, 0, 0 };
 	int gc_mode, gc_type;
 	int err = 0;
@@ -2004,25 +2028,8 @@ static int free_segment_range(struct f2fs_sb_info *sbi,
 		f2fs_allocate_segment_for_resize(sbi, type, start, end);
 
 	/* do GC to move out valid blocks in the range */
-	for (segno = start; segno <= end; segno += SEGS_PER_SEC(sbi)) {
-		struct gc_inode_list gc_list = {
-			.ilist = LIST_HEAD_INIT(gc_list.ilist),
-			.iroot = RADIX_TREE_INIT(gc_list.iroot, GFP_NOFS),
-		};
-
-		do_garbage_collect(sbi, segno, &gc_list, FG_GC, true);
-		put_gc_inode(&gc_list);
-
-		if (!gc_only && get_valid_blocks(sbi, segno, true)) {
-			err = -EAGAIN;
-			goto out;
-		}
-		if (fatal_signal_pending(current)) {
-			err = -ERESTARTSYS;
-			goto out;
-		}
-	}
-	if (gc_only)
+	err = f2fs_gc_range(sbi, start, end, dry_run);
+	if (err || dry_run)
 		goto out;
 
 	stat_inc_cp_call_count(sbi, TOTAL_CALL);